Throttle Full Close Switch: Testing and Inspection
CHECKING PROCEDURE:Requirements:
- Accelerator pedal cable adjustment OK.
ELECTRICAL CHECK:
- Remove intake air sound absorber.
- Disconnect harness connector at throttle body.
- Switch multimeter (Fluke 83 or equivalent) to measure resistance (Ohms) and connect between terminals 4 and 6 using jumper wires from connector test kit VW 1594.
Specified Value: 0 ohms (continuity).
- Open throttle slightly.
Specified Value: infinite Ohms (no continuity).
If the specified value is not obtained by opening the throttle slightly, or if the specified value is obtained only by moving the throttle:
- Adjust CTP switch.
If, after adjusting the CTP switch, it is still not possible to obtain the specified function:
- Replace throttle position sensor assembly.
NOTE: If, while checking or adjusting the Closed Throttle Position (CTP) switch, the noise deadener is removed; make sure during re-assembly that there is a tight fit to the throttle body to avoid the possibility of an intake air leak.
ADJUSTMENT PROCEDURE:
- Remove throttle body.
- Loosen two throttle position sensor mounting screws.
- Turn throttle position sensor in direction shown (arrows), without moving throttle valve shaft, until stop can be felt.
- Tighten throttle position sensor in this position.
- Perform Electrical Check of CTP switch again.
- Re-install throttle body and adjust accelerator pedal cable.
CHECKING WIRING BETWEEN CTP SWITCH AND ECM:
Terminal assignments for throttle position sensor connector.:
- Connect VAG 1598/19 test box to ECM harness connector.
- Check wiring for continuity or short to B+ between throttle position sensor connector terminal 4 (GND) and test box socket D12.
Specified Value: max. 1 Ohms
- Check wiring for continuity or short to Ground (GND) between throttle position sensor connector terminal 6 (signal) and test box socket A4.
Specified Value: max. 1 Ohms
If the specified value is not obtained:
- Determine open or short circuit in wiring using wiring diagram; repair as necessary.
TERMINAL ASSIGNMENTS:
6-pin TP sensor: ECM connector A
6 A4
4 Intake manifold Ground (GND)
NOTE: If it becomes necessary to repair or replace any of the throttle position sensor electrical terminals, ONLY replace with gold-plated terminals.